The lyrics are taken from the Jin dynasty poem 《摸鱼儿·雁丘词》 / Catching fish: Lyric of the wild geese’s grave by 元好问 Yuan Haowen. I’ve altered my translation of 情是何物 / what is [that which is known as] love to make it seem more like a title.
Note: I usually put lyrics of songs from mainland media and/or singers in Simplified Chinese, but since this is a classical poem, I’ve left it in Traditional Chinese because that’s my habit when translating poetry. Also, the numbering of the footnotes starts from 4 because I’ve synced it to my translation of the poem.
問世間，
If I might ask the mortal world:
情是何物？
What is that which is known as love?
直教生死相許。
For it has driven them to follow each other in life and death.
天南地北雙飛客，
From south of the skies to north of the earth they roamed, paired wing to wing$^4$ in flight;
老翅幾回寒暑？
How many winters and summers had their ageing wings seen?
歡樂趣，離別苦，
Such joy and delight they harboured, yet it made parting ache with bitterness;
就中更有癡兒女。
Herein they eclipse the sons and daughters of men in the madness of love$^5$.
君應有語：
Like enough, you wish to say:
渺萬里層雲，
Across the vastness of clouds upon clouds spanning ten thousand miles,
千山暮雪，
Over a thousand mountains enveloped by sunsets and snows,
只影向誰去？
Towards whom would a lone silhouette go?